The purpose of this study is to demonstrate the efficacy of Adapalene 0.1% / Benzoyl Peroxide (BPO) 2.5% Gel associated with Lymecycline 300mg Capsules compared to Adapalene 0.1% /Benzoyl Peroxide 2.5% Vehicle Gel associated with Lymecycline 300mg Capsules, in the treatment of moderate to severe acne vulgaris.